CHARGE CONTROL AGENT AND ELECTROPHOTOGRAPHIC NEGATIVE CHARGE TONER

摘要

PROBLEM TO BE SOLVED: To provide electrophotographic negative charge toners which lessen the change in the electrostatic charge quantity by desorption of a charge control agent, lessen the change in toner characteristics, more particularly electrostatic charge quantity at and under high temperature and high humidity or low temperature and low humidity and make bright color toners obtainable and the charge control agent which obtains such toners. SOLUTION: The charge control agent consisting of a copolymer of 1 to 30 wt.% acrylamide methylpropane sulfonate and 99 to 70 wt.% other vinyl monomer copolymerizable therewith or a copolymer of 1 to 30 wt.% acrylamide methylpropane sulfonic acid and 99 to 70 wt.% other vinyl monomer copolymerizable therewith and the electrophotographic negative charge toners into which the charge control agent described above is incorporated at 0.1 to 10 pts.wt. per 100 pts.wt. binder.